class ChatAPI {
  subscribeToFriendStatus(id, changeStatus) {
    // some api with id params
    changeStatus&& typeof changeStatus === 'function' && changeStatus({isOnline: true});
  }

  unsubscribeFromFriendStatus(id, changeStatus) {
    // some api with id params
    changeStatus&& typeof changeStatus === 'function' && changeStatus({isOnline: false});
  }
}

const chatAPI = new ChatAPI();

export default chatAPI;